Chemistry - AMINES Question with Solution | TestHub

Question Explanation:

The question asks which statements are correct regarding the replacement of halogen by –NH₂ group in halides.

Concept :

This question is based on nucleophilic substitution reactions, amination of alkyl halides, relative reactivity of aryl vs alkyl halides, and reaction conditions.

Solution:

Let us analyze each statement:

Replacement of halogen by NH₂ in alkyl halide is a nucleophilic substitution reaction.

Correct- Ammonia (NH₃ ) acts as a nucleophile and replaces the halogen SN² mechanism depending on the substrate.

1. Aryl halides show more reactivity as compared to alkyl halides in the replacement of halogen by -NH₂ group. Incorrect

2. Aryl halides are less reactive due to resonance stabilization of the C–X bond and partial double bond character. Alkyl halides react more easily.

During the replacement of halogen by –NH group, ammonia is taken in large excess to avoid formation of 2° and 3° amines.

3. Correct -Excess NH₃ suppresses further alkylation of the initially formed 1° amine.

Tertiary alkyl halide generally produces alkene instead of replacement of halogen by NH₂ group. Correct- Tertiary alkyl halides favor elimination (E1/E2) due to steric hindrance, forming alkenes rather than substitution products.